Remove sliceChildren

[aweary]

Another file that looks unused. It's not exposed via any public API like React.Children and is not required anywhere internally in react, react-native, or react-art.

Similar situation as #9107. Looks unused, but maybe not 😄

[sophiebits]

thanks!

[sebmarkbage]

Well this is used by code internally at FB so maybe we should expose it publicly rather than just keeping it as an internal helper?

[gaearon]

It predated toArray. I think we should just change internal callers to use toArray instead.

[sebmarkbage]

Currently the helper is simple but we could optimize it more on our end since we don't have to first create a large array with adjusted/concatenated keys and new elements and then take a small subset of those.

[sebmarkbage]

Like one of our use cases is:

<div>
  {sliceChildren(this.props.children, 0, 1)}
</div>
<div>
  {sliceChildren(this.props.children, 1)}
</div>

This is really inefficient for any significant number of children. Especially if they're nested.

The toArray helper was not added as a best-practice but more as a compromise to make it easy when it doesn't matter but it is still terrible for perf.

EDIT: I suppose in this case, this you would reuse the array which isn't not as bad but also not as good as we could make it with a custom data structure.

[gaearon]

The toArray helper was not added as a best-practice but more as a compromise to make it easy when it doesn't matter but it is still terrible for perf.

Ah okay. My concern was the opposite: the method really makes you think it's optimized but uses toArray under the hood.

[sebmarkbage]

Maybe we should just unify on lodash's lazy evaluation chained "Seq Methods".